This application claims the priority of Korean Patent Application No. 2003-80347, filed on Nov. 13, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to an azimuth calibration of an electronic compass, and more particularly, to an apparatus and method for calibrating an azimuth of a mobile device having an electronic compass, without rotating the mobile device.
2. Description of the Related Art
An electronic compass comprising a magnetic sensor such as a fluxgate device or a magneto-resistive device is widely used in order to recognize a heading direction of mobile devices such as intelligent vehicles, mobile robots, unattended aircrafts, and the like. However, an electronic compass has an azimuth error since a metal substance disturbs the earth's magnetic field if the metal substance is placed around the electronic compass.
To avoid an erroneous result in the heading direction of a mobile device, the rotation of the mobile device having the electronic compass is evaluated in units of time, and if the mobile device rotates 360°, magnetic field data is obtained and the azimuth error is calibrated by means of the magnetic field data. In a situation where the azimuth error is not calibrated, the mobile device will move in a wrong direction specified by an orientation value affected by the azimuth error.